building a FAST legal small block

66 dartman dont ever mention the stock d-dart again dang it, I passed on one for 100 bux from an 81 yo guy back in the 80s .he kept telling me it was special and wanted 100 bux for it. I didnt buy it but it had 4 speed with console 273, believe the cam was solid .528 ,it had cast iron headers, and would flat out fly, I would say im interested in it and then just take it out for joyrides lol 1 of 50 built I now hear